Air operated engagement means for impulse coupled magnetos



G. STEVEN 2 Sheets-Sheet l GEORGE STEVEN INVENTOR.

Dec 11, 195% AIR OPERATED ENGAGEMENT MEANS FOR IMPULSE COUPLED MAGNETOSFiled Dec. 5, 195g H, 1956 STEVEN 23%,493

AIR OPERATED ENGAGEMENT MEANS FOR IMPULSE COUPLED MAGNETOS Filed Dec. 5,1952 2 Sheets-Sheet 2 GEORGE STEVEN ZN V EN TOR.

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United States Patent AIR OPERATED ENGAGEMENT MEANS FOR IMPULSE COUPLEDMAGNETOS George Steven, Kenmore, N. Y., assignor to WorthingtonCorporation, Harrison, N. J., a corporation of Delaware ApplicationDecember 5, 1952, Serial No. 324,302

Claims. (Cl. 123-479) This invention relates generally to an impulse formagnetos and more particularly to an air operated means to control theoperation of the impulse coupling.

Automatic impulse couplings of various types are well known in the artand generally include a rotary or centrifugal element which duringstarting up of an engine coacts with a releasable means so that itdelivers spurts or periodic rotary motion for rotating the armature ofthe magneto of the engine at a speed to actuate the magneto so that itwill be capable of delivering a hot enough spark to fire the engine.Such operation continues during starting up of the engine until suchtime as the speed of the engine increases to a point where the enginewill be able to drive the magneto directly.

It has been found, however, that these releasable mechanisms coactingwith centrifugal devices are unduly noisy during normal operation of theengine and wear out quite quickly.

The present invention overcomes this problem by providing an engagementmeans or releasable means actuated by the engine starting air whichcoacts with the rotary or centrifugal element of the impulse couplingfor the magneto of the engine during starting up so that the magnetowill deliver a spark to the respective ignition means in the cylindersof the engine in accordance with the desider timing cycle thereof, whichengagement means can be rendered inoperative after the engine hasattained operating speed suiiicient to actuate the magneto by directdrive.

With this and other objects in view, as may appear from the accompanyingspecification, the invention consists of various features ofconstruction and combination of parts, which will be first described inconnection with the accompanying drawings, showing an air operatedengagement means for impulse coupled magnetos of a preferred formembodying the invention, and the features forming the invention will bespecifically pointed out in the claims.

In the drawings:

Figure 1 is an elevation of a part of an internal combustion engineshowing the invention applied thereto.

Figure 2 is a top plan of the structure shown in Figure 1.

Figure 3 is a sectional view taken on the line 3--3 of Figure 1illustrating the impulse coupling mechanism of the magneto.

Figure 4 is an enlarged sectional view of the mechanism for operatingthe impulse coupling.

Figure 5 is a detail view taken on line 55 of Figure 1.

Referring more particularly to the drawings, the magnetic impulsecoupling device includes the rotary or centrifugal element 1 havingdiametrically spaced peripheral notches 2 which are engaged successivelyby the pawl or lever 3 and during normal operation of an internalcombustion engine with which the magneto 4 is associated the pawl 3 isheld out of engagement with either of the notches 2 by a spring 5'.

The present invention includes a cylinder which,

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as shown in Figure l of the drawings, may be of hexagonal exterior shapehaving a threaded portion 11 which is threaded into the casing 6 of theimpulse coupling device. A piston 12 is mounted for reciprocatorymovement in the cylinder 10 and it is shown as having a head 13 and anelongated skirt 14 which extends downwardly in the reduced portion ofthe door of the cylinder 10 as is clearly shown in Figure 4 of thedrawings. A spring 15 is mounted in the reduced portion of the door ofthe cylinder 10 and engages the end of the skirt 14. A plunger 16extends through the piston 12 and is threadably carried thereby beingheld in adjusted positions by means of a nut 17. An air conduit 18connects the end of the cylinder 10 facing the free end of the head 13of the piston 12 with a distributor block 19 which is in turn connectedby means of a conduit 20 to the pressure air starting system of theinternal combustion engine with which the magneto is associated.

A three-way valve 21 is interposed in the conduit 20 before thedistributor block 19 and is manually operated by means of a suitablehandle 22. The rotatable core 23 of the three-way valve has three portstherein so that in one position of the valve pressure air from thestarting system of the engine flows from the conduit 20 through thevalve 21 to the distributor block 19 and from the distributor block 19through the conduits 18 to each of the magneto structures employed onthe engine. The third port in the core 23 opens out through an escapevent 24 when the valve core 23 is rotated to cut oil the supply ofpressure air to the distributing block 19, thus allowing the pressureair from the conduit 20 to escape to atmosphere. This construction isprovided to permit prestart operation of the engine before operation ofthe magnetos, the three-way valve structure 21 permitting the normalprestart turning over of the engine without functioning of the impulsecoupling and at the same time the bleeding of air from the vent 24serves as a warning signal to the operator so that after completion ofthe prestart operation he will be advised that the magneto impulsecoupling device is inoperative and that the valve must be operated torender this structure operative for starting the engine.

During the normal operation of the engine the pawl 3 will be held awayfrom the rotating element 1 bymeans of the spring 5 but when startingthe engine or upon application of starting air to the engine, part ofthe starting air will be delivered to the cylinder 10 acting upon thepiston 12 and forcing the plunger 16 into contact with the pawl 3. Thiswill engage the pawl 3 with one of the notches 2 in the rotating element1 when rotation has developed to that point and when the impulse actionon the magneto has developed the pawl 3 becomes disengaged and ridesupon the perimeter of the rotor 1 dropping into the second notch when ithas progressed to its proper position, causing the development of asubsequent impulse in the magneto. The compressible characteristic ofthe pressure air in the cylinder 10 provides for the necessary upwardmovement of disengagement of the pawl or latch 3 when required, but willalways reposition the pin or latch 3 so long as starting air pressure isdelivered to the cylinder. When the starting air is turned off oroperation of the engine is discontinued under action of the starting airthe delivery of starting air to the cylinder 10 will consequently bediscontinued and the latch or pawl 3 will be removed from contact withthe rotating element 1 and will remain in that position until furtherstarting becomes necessary.

By adjustment of the nut 17 the impact of the plunger 16 against thepawl or latch 3 may be regulated.

It will be understood that the invention is not to be limited to thespecific construction or arrangement of parts shown, but that they maybe widely modified within the invention defined by the claims.

What is claimed is:

1. In combination with an internal combustion engine including astarting air system, a magneto and an impulse coupling for said magneto,of pressure actuated means for engaging said impulse coupling inoperative condition upon application of pressure thereto and disengagingsaid impulse coupling upon release of pressure from said pressureactuated means, and a three-way valve in said air starting system forcontrolling the delivery of engine starting air to said pressureactuated means.

2. In combination with an internal combustion engine including astarting air system, a magneto and an impulse coupling for said magneto,said impulse coupling including a rotary element, a pawl for engagementtherewith and a spring for normally holding said pawl out of engagementwith said rotating element, a plunger for engagement with said pawl formoving it into operative engagement with said rotating element, andmeans for delivering pressure air from the engine starting air systemagainst said plunger to move it into pawl engaging position inaccordance with the normal starting operation.

3. in combination with an internal combustion engine including astarting air system, a magneto and an impulse coupling for said magneto,said impulse coupling including a rotary element, a pawl for engagementtherewith and a spring for normally holding said pawl out of engagementwith said rotating element, a plunger for engagement with said pawl formoving it into operative engagement with said rotating element, andmeans for delivering pressure air from the engine starting air systemagainst said plunger to move it into pawl-engaging position, saidlastnamed means including a three-way valve whereby the flow of pressureair to the plunger may be shut ofi during timing operation of the engineand pressure air bleeding from the valve to create a signal warning 4.The combination as claimed in claim 2 wherein said plunger has a pistonconnected thereto, means for adjusting the relative positions of theplunger and piston to regulate the degree of impact of the plungeragainst said pawl, and means for moving said plunger out of pawlengagingposition upon release of pressure thereagainst.

5. in combination with an internal combustion engine including astarting air system, a magneto and an impulse coupling for said magneto,said impulse coupling including a rotating element, a pawl forengagement therewith, a housing enclosing the pawl and rotating elementand a spring for normally holding said pawl out of engagement with saidrotating element, a cylinder carried by said housing, a piston mountedfor reciprocatory movement in said cylinder, a pawl-engaging plungeradjustably carried by said piston and movable upon application ofpressure against said piston for moving the pawl into operativeengagement with said rotating element, and means for delivering pressureair from the engine starting air system to said cylinder.

References Cited in the tile of this patent FOREIGN PATENTS 325,747Great Britain Feb. 27, 1930

